#include <stdio.h>
#include <ctype.h>  /*required for the character function library*/

int main()
{
    #define MAXCHARS 100
    char message[MAXCHARS];
    void convertToUpper(char []);  /*function prototype*/

    printf("\nType in any sequence of characters:\n");
    gets(message);

    convertToUpper(message);

    printf("The characters just entered, in uppercase are:\n%s\n",message);

    return 0;
}
//this function converts all lowercase characters to uppercase
void convertToUpper(char message[])
{
    int i;
    for(i=0;message[i]!='\0';i++)
    message[i]=toupper(message[i]);
}